The goal of the proposed research is to examine the longer-term effects of the Kids in Transition to School (KITS) intervention, which was designed to enhance school readiness in foster children. The proposed study is a continuation of the original KITS efficacy trial, in which 192 children and their caregivers were randomly assigned to the KITS (n = 102) or the foster care comparison condition (n = 90). The KITS intervention is tailored to the needs of foster children in that it is brief and intensive (to accommodate high mobility due to placement changes) and timed to occur during the summer before the critical transition into kindergarten (to prevent the loss of skills during the summer). Additionally, the intervention is based on a developmental translational model, supported by evidence from prior studies, that specifies pathways from early adversity to subsequent outcomes that are mediated through malleable environmental factors (e.g., parenting practices) and underlying neuroregulatory systems (e.g., the hypothalamic pituitary adrenal axis and regions of the prefrontal cortex involved in executive functioning). Immediate intervention effects on early literacy skills and behavioral and emotion regulation abilities have been demonstrated in the original efficacy trial. In the proposed study, we will examine intervention effects on school functioning (academic and socioemotional competence) and psychosocial functioning (drug-use risk behaviors, drug use, aggressive/antisocial behaviors, deviant peer association, and internalizing behavior) across elementary school. A particular emphasis of this research is drug-use risk behaviors; past research has linked better school functioning to lower intentions to use drugs and later ages at initiation. A secondary aim of the study is to examine outcomes into middle school for subsamples of the children. We will also examine the mediation by key neuroregulatory systems and caregiving characteristics of the effects of early adversity and the intervention on school and psychosocial functioning. Finally, we will conduct cost effectiveness analyses to test whether the cost of the intervention per improvement unit in academic and psychosocial domains is less than the cost of usual services. We propose to follow the children through 5 years of data collection. Multimethod, multiagent data will be collected at the end of every school year through elementary school (and into middle school for subsamples of the children). By the end of the proposed study period, all of the children will have completed fifth grade, and subsamples of the children will have completed sixth and seventh grades. PUBLIC HEALTH RELEVANCE: School readiness is linked to positive school functioning and better psychosocial, educational, and employment outcomes for individuals, areas in which foster children are likely to fare poorly. We will examine the longer- term effects of the KITS intervention, which is designed to improve foster children's school readiness. If the intervention has positive effects across elementary school and early middle school, this could represent a promising path for early preventive intervention with this vulnerable population.